Please answer number 4 please

There are 3 islands A,B,C. Island B is east of island A, 8 miles away. Island C is northeast of A, 5 miles away and northwest of

Nostrana [21]

Answer:

The bearing needed to navigate from island B to island C is approximately 38.213º.

Step-by-step explanation:

The geometrical diagram representing the statement is introduced below as attachment, and from Trigonometry we determine that bearing needed to navigate from island B to C by the Cosine Law:

$AC^{2} = AB^{2}+BC^{2}-2\cdot AB\cdot BC\cdot \cos \theta$ (1)

Where:

$AC$ - The distance from A to C, measured in miles.

$AB$ - The distance from A to B, measured in miles.

$BC$ - The distance from B to C, measured in miles.

$\theta$ - Bearing from island B to island C, measured in sexagesimal degrees.

Then, we clear the bearing angle within the equation:

$AC^{2}-AB^{2}-BC^{2}=-2\cdot AB\cdot BC\cdot \cos \theta$

$\cos \theta = \frac{BC^{2}+AB^{2}-AC^{2}}{2\cdot AB\cdot BC}$

$\theta = \cos^{-1}\left(\frac{BC^{2}+AB^{2}-AC^{2}}{2\cdot AB\cdot BC} \right)$ (2)

If we know that $BC = 7\,mi$ , $AB = 8\,mi$ , $AC = 5\,mi$ , then the bearing from island B to island C:

$\theta = \cos^{-1}\left[\frac{(7\mi)^{2}+(8\,mi)^{2}-(5\,mi)^{2}}{2\cdot (8\,mi)\cdot (7\,mi)} \right]$

$\theta \approx 38.213^{\circ}$

The bearing needed to navigate from island B to island C is approximately 38.213º.

8 0

3 years ago

Marita orders 12 yards of material to make banners if she needs one foot of fabric for each Banner how many banners can she make

AleksandrR [38]

36 banners 12 yards=36Ft

3 0

3 years ago

Read 2 more answers

What times what equals -30 but also can be added together and equal -4

Step2247 [10]

Answer:

Step-by-step explanation:

xy=-30

y=-30/x

x+y=-4

x-30/x=-4

x²-30=-4x

x²+4x-30=0

$x^2+4x-30=0\\x=\frac{-4\pm\sqrt{16+120} }{2} \\=\frac{-4\pm\sqrt{136} }{2} \\=-2\pm\sqrt{39} \\=-2+\sqrt{39} ,-2-\sqrt{39} \\y=\frac{-4}{-2+\sqrt{39} } ,\frac{4}{2+\sqrt{39} }$ $correction write ~-30 ~in~place~of~-4~in~the~end$

5 0

3 years ago

Hahaha I need help again please

attashe74 [19]

It could be 2+1 beacuse it says there are twice as many

5 0

3 years ago

Solve the equation <img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B3%7D%7B8%7Dx%20-%2017%20%3D%2010" id="TexFormula1" titl

Annette [7]

Answer:

x = 72

Step-by-step explanation:

To solve for 'x', isolate it. This means to keep 'x' on one side of the equal sign, while moving the other numbers to the other side. The numbers on the other side will tell you what 'x' equals to.

When 'moving' a number to the other side, you cancel it out where it originally is by doing reverse operations. (Reverse operation pairs are addition/subtraction and division/multiplication). To keep an equation balanced, what you do to one side you have to do to the other.

$\frac{3}{8}x-17=10$ Keep 'x' on the left and move everything over.